As an existent example, Patent Literature 1 describes a transparent adhesive for use in optical members for controlling refractive index in which metal oxide particles having a refractive index of 2.0 or more and a dispersion average particle diameter of 1 nm or more and 20 nm or less are dispersed in a transparent adhesive for use in optical members with easy control for the refractive index, less total reflection or halation of light at an interface relative to a transparent optical substrate, capable of satisfying adhesive properties (adhesion strength, retainability, etc.) and durability such as heat resistance, light fastness, heat and moisture resistance and, in addition, with an aim of avoiding undesired effect on the light transmittance.